use libc::c_int;

use super::Disposition;
use crate::{
	codec::{self, packet},
	ffi::*,
	format::context::common::Context,
	DictionaryRef, Discard, Rational,
};

#[derive(Debug)]
pub struct Stream<'a> {
	context: &'a Context,
	index: usize,
}

impl<'a> Stream<'a> {
	pub unsafe fn wrap(context: &Context, index: usize) -> Stream<'_> {
		Stream { context, index }
	}

	pub unsafe fn as_ptr(&self) -> *const AVStream {
		*(*self.context.as_ptr()).streams.add(self.index)
	}
}

impl<'a> Stream<'a> {
	pub fn id(&self) -> i32 {
		unsafe { (*self.as_ptr()).id }
	}

	pub fn codec(&self) -> codec::Context {
		unsafe { codec::Context::wrap((*self.as_ptr()).codec, Some(self.context.destructor())) }
	}

	#[cfg(feature = "ffmpeg_3_1")]
	pub fn parameters(&self) -> codec::Parameters {
		#[cfg(feature = "ffmpeg_3_1")]
		unsafe {
			codec::Parameters::wrap((*self.as_ptr()).codecpar, Some(self.context.destructor()))
		}

		#[cfg(not(feature = "ffmpeg_3_1"))]
		unsafe {
			codec::Parameters::wrap((*self.as_ptr()).codec, Some(self.context.destructor()))
		}
	}

	pub fn index(&self) -> usize {
		unsafe { (*self.as_ptr()).index as usize }
	}

	pub fn time_base(&self) -> Rational {
		unsafe { Rational::from((*self.as_ptr()).time_base) }
	}

	pub fn start_time(&self) -> Option<i64> {
		unsafe {
			match (*self.as_ptr()).start_time {
				AV_NOPTS_VALUE => None,
				value => Some(value),
			}
		}
	}

	pub fn duration(&self) -> Option<i64> {
		unsafe {
			match (*self.as_ptr()).duration {
				AV_NOPTS_VALUE => None,
				value => Some(value),
			}
		}
	}

	pub fn frames(&self) -> i64 {
		unsafe { (*self.as_ptr()).nb_frames }
	}

	pub fn disposition(&self) -> Disposition {
		unsafe { Disposition::from_bits_truncate((*self.as_ptr()).disposition) }
	}

	pub fn discard(&self) -> Discard {
		unsafe { Discard::from((*self.as_ptr()).discard) }
	}

	pub fn side_data(&self) -> SideDataIter<'_> {
		SideDataIter::new(self)
	}

	pub fn frame_rate(&self) -> Rational {
		unsafe { Rational::from(av_stream_get_r_frame_rate(self.as_ptr())) }
	}

	pub fn avg_frame_rate(&self) -> Rational {
		unsafe { Rational::from((*self.as_ptr()).avg_frame_rate) }
	}

	pub fn metadata(&self) -> DictionaryRef<'_> {
		unsafe { DictionaryRef::wrap((*self.as_ptr()).metadata) }
	}
}

impl<'a> PartialEq for Stream<'a> {
	fn eq(&self, other: &Self) -> bool {
		unsafe { self.as_ptr() == other.as_ptr() }
	}
}

impl<'a> Eq for Stream<'a> {}

pub struct SideDataIter<'a> {
	stream: &'a Stream<'a>,
	current: c_int,
}

impl<'a> SideDataIter<'a> {
	pub fn new<'sd, 's: 'sd>(stream: &'s Stream<'_>) -> SideDataIter<'sd> {
		SideDataIter { stream, current: 0 }
	}
}

impl<'a> Iterator for SideDataIter<'a> {
	type Item = packet::SideData<'a>;

	fn next(&mut self) -> Option<<Self as Iterator>::Item> {
		unsafe {
			if self.current >= (*self.stream.as_ptr()).nb_side_data {
				return None;
			}

			self.current += 1;

			Some(packet::SideData::wrap(
				(*self.stream.as_ptr()).side_data.offset((self.current - 1) as isize),
			))
		}
	}

	fn size_hint(&self) -> (usize, Option<usize>) {
		unsafe {
			let length = (*self.stream.as_ptr()).nb_side_data as usize;

			(length - self.current as usize, Some(length - self.current as usize))
		}
	}
}

impl<'a> ExactSizeIterator for SideDataIter<'a> {}
